High-frequency, transistorized sonar are used in the marine industry to detect and display objects beneath an aquatic vehicle. This technology is useful in all facets of the marine industry including mapping and fish-finding. The present invention has numerous applications in the marine industry, but will be described particularly for fish-finding devices used by the recreational angler.
Sonar transducer assemblies for fish-finding, in general, are attached to the hull of a boat and are positioned to direct the sonar below the boat to accurately transmit and receive acoustic signals. Thus, the transducer assembly is generally positioned to extend below the hull of the boat. Because of its positioning, the transducer assembly is often subject to collide with underwater obstacles, thereby rendering it susceptible to damage or shearing from the boat's hull. To avoid damage or destruction to the assembly, and appended costs involved, it is important to provide means to protect the transducer assembly.
"Kick-up" brackets have been developed which permit upward and rearward rotation of the transducer assembly to reposition the transducer assembly upon contact with an underwater obstacle. These brackets must provide a sturdy mechanical connection when the transducer is in an operative position, i.e., extending beneath the hull of the boat, yet readily permit pivotal movement of the transducer housing upon contact with significant force. The pivotal movement, however, must be restricted until contacted with substantial force. For instance, the transducer assembly will be inoperative at high speeds if the kick-up action results from forces due merely to drag at high speeds. Some prior art devices meet these objectives, but do not produce several of the additional advantages of the present invention. Other prior art devices, however, although effective for their intended purposes, often include structures which inherently are more difficult to fabricate, assemble and repair.
An example of a "kick-up" bracket for sonar transducers mounted to the hull of a boat is U.S. Pat. No. 5,109,364 to Stiner. That patent sets forth a sonar transducer assembly which is retained in an operative position by a snap-fit connection. The snap-fit is provided by interlocking members on the mounting member and the transducer housing, respectively. Thus, upon significant force, the interlocking members may be disengaged to permit pivotal movement of the transducer housing. Another example is U.S. Pat. No. 4,907,208 to Lowrance et al. That patent sets forth a sonar transducer that is mounted to a bracket utilizing lockwashers. The lockwashers act as a clutch to maintain the transducer in a stationary position but which give way to release the connection permitting the transducer assembly to pivot upwardly and rearwardly.
Other prior art connections permitting "kick-up" action are magnetic connections, as set forth in U.S. Pat. No. 5,142,497 to Warrow, and spring biased connections as set forth in U.S. Pat. No. 4,850,559 to Boucher and U.S. Pat. No. 3,729,162 to Salvato. The more complex the assembly, however, the more difficult it is to fabricate, assemble, and repair, thereby making it more costly to the consumer, e.g., the recreational angler.